Device for controllling a movable member

ABSTRACT

A device for controlling a stop position of a movable member includes a movable member movable as far as a specified stop position, drive means for moving the movable member, detection means for detecting that the movable member reaches the specified stop position, timer means for setting a specified time, and control means responsive to detection means for suspending the drive means when the movable member reaches the specified stop position, setting the timer means, then allowing the drive means to drive again until the set time elapses. Also, a device for controlling a lens position of a camera includes a lens setable at one of a projected state and a retracted state, change means for changing the lens from the projected state to the retracted state and vice versa, detection means for detecting that a loaded film is wound by the tail portion, discrimination means for discriminating whether the lens is set in the projected state, rewinding means at least responsive to the detection means for rewinding the wound film when the loaded film is wound by the tail portion, and control means responsive to the detection means, the discrimination means, and the rewinding means for controlling the change means so as to return the lens to the retracted state.

This application is a division of application Ser. No. 07/660,268, filedFeb. 26, 1991, now U.S. Pat. No. 5,124,737 which is a continuation ofapplication Ser. No. 07/346,078, filed May 2, 1989, now abandoned.

BACKGROUND OF THE INVENTION AND RELATED ART STATEMENT

The present invention relates to a device for controlling a movablemember which is applicable for controlling a stop position of a movablelens of a focal length changeable type camera, and also applicable forcontrolling a lens position of a focal length changeable type camera ofrear converter type.

Widely has been used a camera carrying a taking lens capable of changingthe focal length. In such a focal length changeable lens camera, it isusual to move a movable lens by use of an internally equipped motor inresponse to switching operation. Specifically, a lens position detectionswitch detects that the movable lens reaches a specified stop position(i.e. end position) of a telephoto focal length state, standard focallength state, or wide angle focal length state. Subsequently, theinternally equipped motor is suspended or driven in response to outputsof the switch.

In such a focal length changeable lens camera, also, it has beenrequired to change the focal length in prompt response to photographypurposes. Therefore, the movable lens is moved at high speed so that arapid change in focal length is attainable. It could be seen that evenif the movable lens has a small weight, the movable lens has aconsiderably great momentum. Accordingly, even when the movable lens isstopped immediately after the lens position detection switch detectsthat the lens reaches the specified stop position, there is a likelihoodthat the movable lens rebounds at the specified stop position and stopsat a position before the specified stop position. Consequently, there isa likelihood that a designed photography performance can not be obtaineddue to the positional error of the movable lens.

Also, in such a focal length changeable lens camera, changing the focallength changes the projection amount of the lens. In a focal lengthchangeable type camera of rear converter type when the focal lens is setin the telephoto focal length state, the projection amount of the lensis considerably great. This is because the lens must be projectedcorresponding to an amount in which a rear converter lens is introducedbehind the lens retracted. When a loaded film is not wound by the tailportion, it is usual that the lens is required to be set not only in thestandard focal length state (or wide angle focal length state), i.e., aretracted state but also in the telephoto focal length state, i.e., aprojected state.

When the film is wound by the tail portion, there are few occasions thatthe lens is required to be set at the projected state. Also, when thewound film is rewound, there are few occasions that the lens is requiredto be set at the projected state. It could be seen that a considerablyprojected lens lowers the portability of the camera. Accordingly, it isdesired that when the camera is not put into work and is carried, thelens be set in the retracted state.

As mentioned above, in such focal length changeable lens cameras, it isusual to move the movable lens by use of an internally equipped motor inresponse to switching operation. Furthermore, it is usual in such acamera that all the switches of the camera are not allowed to operateduring the time from start of the film rewinding operation to opening ofthe rear cover. Accordingly, there is a disadvantage that when the filmrewinding operation is started with the lens being set in the projectedstate, the lens can not be set from the projected state to the retractedstate until the film rewinding operation is completed and the rear coveris opened. Even if the lens is made changeable from the projected stateto the retracted state even after starting of the rewinding operation,there is another disadvantage that the lens moves uselessly in spite ofthe state that photography is unexecutable.

SUMMARY OF THE INVENTION

The present invention has worked out to overcome the above-mentioneddrawbacks. It is an object of the present invention to provide a devicefor controlling a stop position of a movable member which makes itpossible to stop the movable member at a specified stop position with anincreased accuracy. It is another object of the present invention toprovide a device for controlling a lens position of a camera which makesit possible to automatically return the lens to a retracted state whenthe film is wound by the tail portion or rewinding operation is started.

A first device of the present invention comprises a movable membermovable as far as a specified stop position, drive means for moving themovable member, detection means for detecting that the movable memberreaches the specified stop position, timer means for setting a specifiedtime, and control means responsive to the detection means for suspendingthe drive means when the movable member reaches the specified stopposition, setting the timer means, then allowing the drive means todrive again until the set time elapses.

Accordingly, the first device in which the drive means is temporarilysuspended when the movable member reaches the specified stop position, aspecified time being set, the drive means being then driven again untilthe set time elapses makes it possible to eliminate the movable memberfrom rebounding at the specified stop position and consequently to stopthe movable member at the specified stop position accurately.

A second device of the present invention comprises a lens setable at oneof a projected state and a retracted state, change means for changingthe lens from the projected state to the retracted state and vice versa,detection means for detecting that a loaded film is wound by the tailportion, discrimination means for discriminating whether the lens is setin the projected state, rewinding means at least responsive to thedetection means for rewinding the wound film when the loaded film iswound by the tail portion, and control means responsive to the detectionmeans, the discrimination means, and the rewinding means for controllingthe change means so as to return the lens to the retracted state.

Accordingly, the second device in which the lens is returnable to theretracted state when the loaded film is entirely wound by the tailportion or the rewinding operation is started makes it possible toeliminate the disadvantage that the lens is in the projected state whenphotography is unexecutable for film replacement or other reasons andconsequently set the camera in a compact form when not used. Also, thesecond device can eliminate the above-mentioned disadvantage that whenthe film rewinding operation is started with the lens being in theprojected state, the lens can not be returned to the retracted stateuntil the film rewinding operation is completed and the rear cover isopened. Further, the second device can eliminate the above-mentioneddisadvantage that the lens moves in spite of the state that photographyis unexecutable.

These and other objects, features and advantages of the presentinvention will become more apparent upon a reading of the followingdetailed description and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram showing a basic construction of a device ofthe present invention;

FIG. 2 is a block diagram showing a basic construction of another deviceof the present invention;

FIG. 3 is a block diagram showing an overall construction of a cameraembodying the present invention;

FIGS. 4a and 4b are flowcharts combinedly showing a mainsequence of thecamera, circled A, B, C in FIG. 4a being respectively connected withcircled A, B, C in FIG. 4b;

FIG. 5 is a flowchart showing a focal length change subsequence of thecamera;

FIG. 6 is a flowchart showing a film rewinding subsequence of thecamera, circled A in FIG. 6 being connected with the circled A in FIG.4a; and

FIG. 7 is a flowchart showing another film rewinding subsequence of thecamera, circled A in FIG. 7 being connected with the circled A in FIG.4a.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Referring to FIG. 1, firstly, a device of the present inventionbasically comprises a movable member 1 movable as far as a specifiedstop position P but immovable beyond the specified stop position P,drive means 2 for moving the movable member 1, detection means 3 fordetecting that the movable member 1 reaches the specified stop positionP, timer means 4 for setting a specified time, and control means 5 forsuspending the drive means when the movable member 1 reaches the stopposition P, setting the timer means 4 at the specified time, andallowing the drive means to drive again until the specified timeelapses.

The movable member 1 is moved to and stopped at the specified stopposition P in the following way. The timer means 4 and the control means5 are not put into operation and the drive means 2 continues to move themovable member 1 until the movable member 1 reaches the specified stopposition P. When the detection means 3 detects that the movable member 1reaches the specified stop position P, the control means 5 suspends thedrive means 2 in response to the detection means 3 and simultaneouslysets the timer at the specified time. After the timer means 4 is set,the drive means 3 is put into operation again. After the lapse of thespecified time, i.e., the timer means 4 comes to a stop and the drivemeans 2 is then suspended again.

In other words, when the movable member 1 reaches the specified stopposition P, the drive means 2 is temporarily stopped and then put intooperation again for the specified time. Accordingly, it could be seenthat even if the movable member rebounds at the specified stop position,the movable member can be stopped at the specified stop position owingto the fact that the movable member 1 is moved to the specified stopposition P for the specified time.

It could be seen that there is a likelihood that in the above-mentionedre-movement, the movable member 1 repeatedly rebounds at the specifiedstop position P. However, the momentum of the movable member 1 decreasesas time passes and the oscillation consequently dampens. Accordingly, itwill be theoretically apparent that the longer the specified time isset, the closer the movable member is stopped to the specified stopposition P. However, it is practical to set the specified time at such atime as to assure an intended stop accuracy.

Next, referring to FIG. 2, another device of the present inventioncomprises a lens 6 setable in one of a projected state and a retractedstate, change means 7 for changing the lens 6 from the projected stateto the retracted state and vice versa, detection means 8 for detectingthat a loaded film is wound by the tail portion, discrimination means 9for discriminating whether the lens 6 is in the projected position,rewinding means 10 at least responsive to the detection means 8 forrewinding the film when the loaded film is wound by the tail portion,and control means 11 responsive to the detection means 8, thediscrimination means 9, and the rewinding means 10 for controlling thechange means 7 so as to return the lens 6 to the retracted state whenthe lens is set in the projected state after the loaded film is wound bythe tail portion or rewinding operation of the wound film is started.

It will be noted that one of the detection means 8 and the rewindingmeans 9 may be omitted. Specifically, in the case of omitting thedetection means 8, the control means 11 is made to control the changemeans 7 in response to manually operated rewinding. In the case ofomitting the rewinding means 10, the control means 11 is made to controlthe change means 7 in response to the detection means 8.

The second device is operated in the following way. The detection means8 detects that the loaded film is wound by the tail portion. Therewinding means 10 then starts the rewinding operation in response tothe above detection. On the other hand, the control means 11 receiveslens state information from the discrimination means 9 and rewindingoperation information from the rewinding means 10. If the lens 6 is setin the projected state and the rewinding operation is started, thecontrol means 11 controls the change means 7 so as to return the lens 6to the retracted position.

In the case of omitting the rewinding means 10, the control means 11receives lens state information from the discrimination means 9 and filminformation from the detection means 8. If the lens 6 is set in theprojected state and the loaded film is wound by the tail portion, thecontrol means 11 controls the change means 7 so as to return the lens 6to the retracted state.

In the case of omitting the detection means 8, the control means 11receives lens state information from the discrimination means 9 andrewinding operation information from the rewinding means 10. If the lens6 is set in the projected state and the rewinding operation is started,the control means 11 controls the change means 7 so as to return thelens 6 to the retracted state.

Next, the present invention will be described with reference to FIG. 3showing a general circuit of a camera embodying the present invention.Indicated at BA is a battery, e.g., a lithium cell. The battery BA isconnected with a light/distance measurement circuit AFE for measuringbrightness and distance of and to an object to be photographed, and aninterface unit IF for controlling motors M1, M2, M3, M4 through a lineVee. Also, a series line of a diode D1 and a capacitor C1 is parallelconnected to the battery BA. The cathode line Vdd of the diode D1 isconnected to a microcomputer MC.

The capacitor C1 has a relatively great capacitance, so that when thebattery is removed to be replaced with a fresh battery, the capacitor C1can give a supply of electricity to the microcomputer MC through theline Vdd. At this time, the diode D1 keeps an electric current fromreversely flowing from the capacitor C1 to the line Vee. Also, it willbe seen that when a great amount of electric current flows through theline Vee to drive the motor or other means, the voltage of the line Veelowers due to the internal resistance of the battery BA. However, thediode D1 keeps an electric current from reversely flowing from thecapacitor C1 to the line Vee. Accordingly, the power line Vdd of themicrocomputer MC is held at a stabilized voltage, which consequentlyprevents the microcomputer MC from coming into unintentional stop oruncontrollable states.

The microcomputer MC has a number of input ports respectively connectedto a variety of switches which will be described below.

Indicated at Src is a rear cover switch which is turned on or off inaccordance with opening and closing of a rear cover of the camera. Whenthe rear cover is opened, the switch Src is turned on. When the rearcover is closed, the switch Src is turned off.

Indicated at Srew is a rewinding switch which is manually actuated whenthe film is forcefully rewound. The switch Srew is put in the OFF-statein usual time. When the switch Srew is turned on, the rewindingoperation of film is started. After starting the rewinding operation,the microcomputer allows the rewinding operation to continue until thefilm is completely rewound. Even if the switch Srew is turned off, therewinding operation is maintained until completed.

Indicated at So is a lens barrier switch which is turned on or off inaccordance with opening and closing of a lens barrier of the camera.When the lens barrier is put in the opened-state, the switch So is heldin the ON-state. When the lens barrier is put in the closed-state, theswitch So is held in the OFF-state. When the lens barrier is put in theclosed-state, all the photography operations are suspended.

Indicated at S1 is a light/distance measurement switch which is turnedon when a release button is pressed down halfway. When the switch S1 isturned on, operation of measuring brightness and distance of and to theobject is started.

Indicated at S2 is a release switch which is turned on when the releasebutton is pressed down all the way. When the switch S2 is turned on, arelease sequence is started.

Indicated at Sst is a switch for changing the focal length of a takinglens. The switch Sst is put in the OFF-state in usual time. Everyturning-on of the switch Sst changes the focal length of the takinglens.

Indicated at Sstd, Stele are switches for detecting the stop position ofa movable lens of the taking lens. When the movable lens is set at astandard stop position, e.g., a focal length of 35 mm, the standard stopposition detection switch Sstd is turned on. When the movable lens isset at a telephoto stop position, e.g., a focal length of 70 mm, thetelephoto stop position detection switch Stele is turned on. In the casethat the taking lens is a zoom lens, it may be appropriate to constitutethese switches Sstd, Stele by use of a contact of a zoom encoder whichis provided on the zoom lens to issue signals concerning focal lengths.

Indicated at Swnd is a switch for detecting one-frame winding of thefilm. The switch Swnd is operably connected with a film winding sprocketand thereby tuned on every one-frame winding.

Indicated at Sflm is a switch for detecting the presence of a film. Theswitch Sflm is turned on when the film occupies an image section of thecamera.

One of the ends of all the above-mentioned switches are grounded and theother ends are connected to their respective input ports of themicrocomputer MC. The other ends connected to the input ports are pulledup in the microcomputer MC. Accordingly, the input port end of eachswitch is put in the HIGH-level when the switch is turned off, and putin the LOW-level when the switch is turned on. The microcomputer MCdetects the level state of each switch to discriminate the ON/OFF stateof the switch.

The light/distance measurement circuit AFE measures the brightness ofthe object and the distance to the object in accordance with commands ofthe microcomputer MC and sends measured results to the microcomputer MC.

The motor M1 is adopted for changing the focal length of the takinglens. The motor M2 is adopted for winding or rewinding the film. Whenthe motor M1 is driven in the normal direction, the movable lens ismoved to the telephoto stop position. When the motor M1 is driven in thereverse direction, the movable lens is moved to the standard stopposition. Also, when the motor M2 is driven in the normal direction, thefilm is wound. When the motor M2 is driven in the reverse direction, thefilm is rewound.

The motors M3, M4 are bipolar-driven stepping motors oftwo-phase-excitation type. When the stepping motor M3 is driven in thenormal direction, a focusing lens is moved forward. When the steppingmotor M3 is driven in the reverse direction, the focusing lens isreturned to an original position. When the stepping motor M4 is drivenin the normal direction, a shutter is opened. When the stepping motor M4is driven in the reverse direction, the shutter is closed.

The motors M1, M2, and the stepping motors M3, M4 communicate with themicrocomputer MC through the interface unit IF. The interface unit IFconsists of interface members IF1, IF2, IF3, and IF4 which will bedescribed below.

The interface member IF1 is adopted for controlling the focal lengthchange motor M1. The interface member IF1 combines outputs from outputports ST1, ST2 of the microcomputer MC to drive the motor M1 in thenormal direction or the reverse direction to brake the rotation of themotor M1, or suspend the electric flow to the motor M1.

The interface member IF2 is adopted for controlling the filmwinding/rewinding motor M2. The interface member IF2 combines outputsfrom output ports WND1, WND2 of the microcomputer MC to drive the motorM2 in the normal direction or the reverse direction to brake therotation of the motor M2, or suspend the electric flow to the motor M2.

The interface member IF3 is adopted for controlling the stepping motorM3. The interface member IF3 controls the stepping motor M3 inaccordance with outputs from output ports STM1, STM2, STM3 of themicrocomputer MC. Specifically, the output port STM1 is used forchanging the direction of electric current flowing to a first coil L1 ofthe stepping motor M3. The output port STM2 is used for changing thedirection of electric current flowing to a second coil L2 of thestepping motor M3. The output port STM3 is used for suspending theelectric currents flowing to the coils L1, L2.

The interface member IF4 is adopted for controlling the stepping motorM4. The interface member IF3 controls the stepping motor M4 inaccordance with outputs from output ports STM4, STM5, STM6 of themicrocomputer MC. Specifically, the output port STM4 is used forchanging the direction of electric current flowing to a first coil L3 ofthe stepping motor M4. The output port STM5 is used for changing thedirection of electric current flowing to a second coil L4 of thestepping motor M4. The output port STM6 is used for suspending theelectric currents flowing to the coils L3, L4.

A photography main sequence of the camera will be described below withreference to FIGS. 4a and 4b.

When the camera is not put in any operation, the sequence is held atStep #1 at which it is discriminated whether any change occurs in theinput ports to which the switches are respectively connected. When anychange occurs, the sequence advances to Step #2. When no change occurs,the above-mentioned discrimination is repeated.

At Step #2, it is discriminated whether the rear cover is opened or therear cover switch Src is turned on. When the rear cover is opened, i.e.,the rear cover switch Src is turned on, the sequence advances to Step#7. When the rear cover is closed, i.e., the rear cover switch Src isturned off, the sequence advances to Step #3 at which it isdiscriminated whether the closed-state is produced immediately after thecamera is loaded with a film, that is, whether it is an initial closedstate.

When it is YES at Step #3, i.e., the closed-state is producedimmediately after loaded with the film, the sequence advances to Step #4at which initial loading operation of the film is practiced and thenreturns to Step #2. When it is NO at Step #3, i.e., the closed state isnot produced immediately after loaded with the film, the sequenceadvances to Step #5 at which it is discriminated whether the rewindingswitch Srew is turned on.

When the rewinding switch Srew is turned on, the sequence advances toStep #6 at which rewinding operation of the film is practiced. When therewinding switch Srew is not turned on, the sequence advances to Step #7at which it is discriminated whether the lens barrier switch So isturned off.

When the lens barrier switch So is turned off, the sequence advances toStep #8 at which it is discriminated whether the movable lens is set atthe telephoto stop position. The discrimination is practiced based onwhether a focal length change flag Ftele is "1". When the movable lensis at the telephone stop position, the flag is set at "1". When themovable lens is at the standard stop position, the flag is set at "0".

When the flag is "1" at Step #8, i.e., the movable lens is set at thetelephoto stop position, the sequence advances to Step #9 at which afocal length change subsequence is carried out and then returns to Step#2. The focal length change subsequence will be described later. Whenthe flag is "0" at Step #8, i.e., the movable lens is set at thestandard stop position, the sequence returns to Step #1 without changingthe focal length of the taking lens. At Step #1, then, it is checkedwhether there is any change in the switches.

When the lens barrier switch So is turned on, i.e., the lens barrier isopened, the sequence advances to Step #10 at which it is discriminatedwhether the light/distance measurement switch S1 is turned on.

When the light/distance measurement switch S1 is turned off, thesequence advances to Step #11 at which it is discriminated whether thefocal length change switch Sst is turned on.

When the focal length change switch Sst is turned on, the sequenceadvances to Step #12 at which the focal length change subsequence isthen carried out. Thereafter, the sequence returns to Step #1. When thefocal length change switch Sst is turned off, the sequence returnsdirectly to Step #1.

When the light/distance measurement switch S1 is turned on, the sequenceadvances to Step #13 at which the light/distance measurement ispracticed.

Subsequently, the sequence advances to Step #14 at which it is alsodiscriminated whether the light/distance measurement switch S1 is turnedon. When the light/distance measurement switch S1 is turned off, thesequence returns to Step #2.

When the light/distance measurement switch S1 is turned on, the sequenceadvances to Step #15 at which it is discriminated whether the releaseswitch S2 is turned on. When the release switch S2 is in the OFF-state,the sequence advances to Step #14. The sequence repeats thediscriminations of Steps #14, #15 until the release switch S2 is turnedon. When the light/distance measurement switch S1 is turned off, thesequence returns to Step #2 and repeats the above-mentioned steps.

When the release switch S2 is turned on, the sequence advances to Step#16 at which the focusing lens is moved forward in accordance withdistance data obtained at Step #13. The sequence advances then to Step#17 at which exposure is practiced in accordance with light dataobtained at Step #13. After the exposure is completed, the sequenceadvances to Step #18 at which the focusing lens is returned to theoriginal position and then advances to Step #19 at which a timer is setat 1.5 seconds and then started. The timer issues a time-up signal afterthe lapse of 1.5 seconds.

Simultaneously, at Step #20, the motor M2 is driven in the normaldirection to wind the film. At Step #21, it is discriminated whether thewinding switch Swnd is turned on. At Step #23, it is discriminatedwhether the timer issues a time-up signal. When the winding switch Swndis turned on before the timer issues the time-up signal, i.e., thewinding switch Swnd is turned on at Step #21, in other words, the filmis wound one frame, the sequence advances to Step #22 at which the motorM2 is then suspended and returns to Step #1. When the timer issues thetime-up signal before the winding switch Swnd is turned on, i.e., thetimer issues the time-up signal at Step #23, in other words, the time of1.5 seconds elapse without winding the film one frame, the sequenceadvances to Step #24 at which it is discriminated whether the filmdetection switch Sflm is turned on to confirm the presence of the film.

When the film detection switch Sflm is turned on, in other words, it ismeant that the film is wound by the tail portion, the sequence advancesto Step #25 at which the motor M2 is suspended and then advances to Step#26 at which a film rewinding subsequence is carried out. The rewindingsubsequence will be described later. When the film detection switch Sflmis turned off, in other words, it is meant that the camera is loadedwith no film, the sequence returns to Step #22 and returns to Step #1.

In this mainsequence, the timer is set at the time of 1.5 seconds todetect a tail portion of the film. However, it should be noted that anappropriate time is set in accordance with winding mechanisms ofcameras. It should be noted that the time of 1.5 seconds is mentioned asone example.

The focal length change subsequence will be described with reference toFIG. 5. At Step #101, it is discriminated whether the focal lengthchange flag is "0". When the flag is "0", i.e., the movable lens is setat the standard stop position, the motor M1 is turned so as to move themovable lens from the standard stop position to the telephoto stopposition. Specifically, the subsequence advances to Steps #102, #103 atwhich the motor is driven in the normal direction until the telephotostop position detection switch Stele is turned on.

When the movable lens is set at the telephoto stop position, i.e., thetelephoto stop position detection switch Stele is turned on at Step#102, the subsequence advances to Step #104 at which the flag is set at"1". At Step #108, then, braking of the motor M1 is started. The brakingis held for 2 milliseconds at Step #109.

However, it should be noted that the movable lens can not be stoppedimmediately after the motor is braked due to the inertial force of themovable lens. Accordingly, it could be seen that the movable lens isliable to rebound at the telephoto stop position and then move back alittle to the standard stop position.

For this reason, it is discriminated at Step #110 whether the focallength change flag is "1" in order to determine which direction themotor M1 is required to drive in. The motor M1 is driven in the reversedirection at Step #111 and in the normal direction at Step #112.

In this subsequence in which the flag is set at "1" at Step #104, thesubsequence advances to Step #112 at which the motor M1 is driven in thenormal direction so as to move the movable lens to the telephoto stopposition. The driving of the motor M1 is held for 30 milliseconds atStep #113. The motor M1 is braked at Step #114. The braking is held for100 milliseconds at Step #115. At Step #116, the electric flow to themotor M1 is suspended. Then, the subsequence returns to the mainsequence at Step #117.

In the case of moving the movable lens from the telephoto stop positionto the standard stop position, similar subsequence is carried out. Whenthe focal length change flag is "1", it is meant that the movable lensis set at the telephoto stop position. Accordingly, the motor M1 isturned so as to move the movable lens from the telephoto stop positionto the standard stop position. Specifically, the subsequence advances toSteps #105, #106 at which the motor M1 is driven in the reversedirection until the standard stop position detection switch Sstd isturned on.

When the movable lens is set at the standard stop position, i.e., thestandard stop position detection switch Sstd is turned on at Step #105,the subsequence advances to Step #107 at which the flag is set at "0".At Step #108, then, braking of the motor M1 is started. The braking isheld for 2 milliseconds at Step #109.

However, the movable lens can not be stopped immediately after the motoris braked due to the inertial force of the movable lens. Consequently,the movable lens is liable to rebound at the standard stop position andthen move back a little to the telephoto stop position.

Accordingly, it is discriminated at Step #110 whether the focal lengthchange flag is "0" in order to determine which direction the motor M1 isrequired to drive in. In this subsequence in which the flag is set at"0" at Step #107, the subsequence advances to Step #111 at which themotor M1 is driven in the reverse direction so as to move the movablelens to the standard stop position. The driving of the motor M1 is heldfor 30 milliseconds at Step #113. The motor M1 is braked at Step #114.The braking is held for 100 milliseconds at Step #115. At Step #116, theelectric flow to the motor M1 is suspended. Then, the subsequencereturns to the main sequence at Step #117.

It should be noted that the distance in which the movable lens is movedat the re-driving of Steps #111, 112 is considerably small. Accordingly,it could be seen that rebounds of the movable lens are eliminated in theredriving of 30 milliseconds and focal length change can be accuratelycarried out.

Also, it should be noted that the times which are set at Steps #109,#113, and #115 are appropriately set in accordance with focal lengthchange mechanisms. The above-mentioned times, 2 milliseconds at Step#109, 30 milliseconds at Step #113, and 100 milliseconds at Step #115,are mentioned as examples.

Next, the film rewinding subsequence will be described with reference toFIG. 6. The subsequence is started when the rewinding switch Srew isturned on, or the tail portion of the film is detected. At Step #201, itis discriminated whether the focal length change flag is "1".

When the flag is "1", i.e., the movable lens is set at the telephotostop position, the subsequence advances to Step #202 at which themovable lens is returned to the standard stop position in accordancewith the above-mentioned focal length change subsequence, and thenadvances to Step #203.

When the flag is "0", i.e., the movable lens is set at the standard stopposition, the subsequence advances to Step #203.

At Step #203, it is started driving the motor M2 in the reversedirection to rewind the film. To check whether the rewinding operationis completed, at Step #204, it is discriminated whether the filmdetection switch Sflm is turned on. When the switch Sflm is in theON-state, i.e., the rewinding operation is not completed, thediscrimination of Step #204 is repeated until the film is almostcompletely rewound and the switch Sflm is turned off. Subsequently, themotor M2 is stopped at Step #205 and the rewinding operation comes tocompletion.

The subsequence advances to Step #206 at which it is repeated todiscriminate whether the rear cover switch Src is turned on until therear cover is opened. All the other switches are suspended until therear cover switch Src is turned on. This suspension warns the user tounload the film from the camera.

When the rear cover is opened to unload the film, i.e., the rear coverswitch Src is turned on, the subsequence returns to Step #2 of the mainsequence.

It should be noted that while the movable lens is moved before rewindingin the above-mentioned film rewinding subsequence, the movable lens maybe moved after rewinding as another film rewinding subsequence shown inFIG. 7.

The operation of each step of the subsequence of FIG. 7 is the same asthe subsequence of FIG. 6 except for a fact that in the subsequence ofFIG. 7, Steps #201, #202 of the subsequence of FIG. 6 (i.e., the movablelens movement) and Steps #203, #204, #205 (i.e., the film rewinding) arereplaced with one another.

In usual time, however, the subsequence of FIG. 6 is better than thesubsequence of FIG. 7. This is because there is a likelihood in thesequence of FIG. 7 that the user is surprised at unexpectable movementof the movable lens after the rewinding operation is completed. In thecase that the lens barrier is closed during the time that the rewindingoperation is practiced, particularly, it is usual that the user does notexpect the movable lens to move after the lens barrier is closed.Accordingly, it is more preferably to move the movable lens before therewinding operation is started than after the rewinding operation iscompleted.

As mentioned above, the subsequence of FIG. 6 or the subsequence of FIG.7 makes the movable lens set at the standard stop position before therewinding operation is started or after the rewinding operation iscompleted. Accordingly, it is not necessary to permit the focal lengthchange when the rewinding operation is completed. Thus a simplifiedsequence can be provided. Also, the drawback can be eliminated which themovable lens moves in the state that photography is unexecutable.Consequently, the camera can be handled without involving uneasiness.

Furthermore, it would be understood that the foregoing relates to onlythe scope of the present invention as defined by the appended claimsrather than by the description preceding them, and all changes that fallwithin metes and bounds of the claims, or equivalent of such metes andbounds are therefore intended to be embraced by the claims.

What is claimed is:
 1. A device for controlling the position of amovable member of a camera, comprising:a movable member movable betweenan extended position and a retracted position, means for moving saidmovable member between the two positions, means for detecting a statethat a photographing operation of the last photographic frame of aloaded film is completed, and means, responsive to said detecting means,for controlling said moving means to move said movable member to theretracted position when said detecting means detects the state.
 2. Adevice for controlling the position of a movable member of a camera,comprising:a movable member movable between an extended position and aretracted position, means for moving said movable member between the twopositions, means for feeding a photographic frame of a film at everyphotographing operation, means for rewinding the film, and means,responsive to said rewinding means, for controlling said moving means tomove said movable member to the retracted position when the filmrewinding is started.
 3. A device for controlling the position of amovable member of a camera, comprising:a movable member movable betweenan extended position and a retracted position, means for moving saidmovable member between the two positions, means for feeding photographicframe of a film at every photographing operation, means for rewindingthe film, and means, responsive to said rewinding means, for controllingsaid moving means to move said movable member to the retracted positionbefore the film rewinding is started.
 4. A device for controlling theposition of a movable member used in a camera wherein a recording meansloaded in the camera records an image of an object, said devicecomprising:a movable member movable between an extended position and aretracted position, means for moving said movable member between the twopositions, means for detecting a state that capacity of the recordingmeans is not available for one further photographing operation, andmeans, responsive to said detecting means, for controlling said movingmeans to move said movable member to the retracted position when saiddetecting means detects said state.
 5. A device according to claim 4wherein the recording means is a film.